Application of a 0.2% nitroglycerin ointment may help heal
a long-term (chronic) tear, or
fissure, in the
anus. You rub a pea-sized dot of cream on the fissure
twice a day. It is a good idea to either wear gloves when applying the
nitroglycerin cream or wash your hands right after. The skin on your fingers
can absorb the medicine and increase your chance of side effects.
An increase in muscle tension, also called resting pressure, in the
internal anal sphincter can lead to fissures. Spasms and reduced blood flow to
the anus may occur along with the rise in pressure, causing fissures or keeping
existing fissures from healing.
Nitroglycerin is usually the first
medicine used to treat a chronic anal fissure. Many studies have shown that it
works better than conservative treatment (eating more fiber and taking
sitz baths).footnote 1
Headaches are the main side effect of nitroglycerin ointment. The risk of
headaches and lightheadedness from low blood pressure is especially high if you
use too much ointment at one time.
Some people also may
experience itching or burning in the anal area. In some cases, people may
develop tolerance to nitroglycerin, meaning that after a while the ointment no
longer works to reduce muscle tension.
People using nitroglycerin
ointment have increased chances of having low blood pressure. So you should not
use nitroglycerin ointment within 24 hours of taking sildenafil (Viagra),
tadalafil (Cialis), or vardenafil (Levitra).
Nelson R (2006). Non-surgical therapy for anal fissure. Cochrane Database of Systematic Reviews (4).